The launch of Apple's new iCloud service has been reminiscent of the fiasco three years ago when the company debuted MobileMe, according to users' complaints that describe a sweeping range of problems.

iCloud, which Apple launched Wednesday, is the free replacement for MobileMe, the sync service that had major teething troubles in 2008. MobileMe stumbled badly then, dogged by problems ranging from slow synchronization to an 11-day email outage.

iCloud has gotten off to a rocky start, showing some users this message when they try to migrate from MobileMe.

"You might ask, 'Why should I believe them, they're the ones that brought me MobileMe?'" Jobs said to loud laughter from the crowd as he touted iCloud. "It wasn't our finest hour, just let me say that. But we learned a lot."

Apparently not, at least by the volume and variety of complaints users have posted to Apple's support forums for iCloud.

Those reports have detailed a large number of issues with the service, ranging from an inability to log on using long-owned Apple IDs and overloaded servers that won't process MobileMe migration requests to iOS online backup failures and duplicating Safari bookmarks.

Several Computerworld staffers have encountered many of the same problems detailed in the support forums.

One of the fastest-growing complaints, however, is about iCloud's failure to deliver emails, or let users log onto their .me or .mac accounts.

"Don't upgrade [to iCloud] unless you want to do without email for a few days," said someone identified as "Roger Tennessee" earlier today. "This is a disaster if you depend on your .mac or .me [account] for mail. WARNING!!!!"

"Ever since moving to iCloud with my MacBook Pro and iPad, Apple's Mail App on both the iPad and my MBP are telling me that they cannot access my me.com email," echoed "papa-kostas.".

Apple has acknowledged problems with iCloud's mail.

"Some users are experiencing intermittent authentication errors when trying to use mail," stated the iCloud status monitor today. "Normal service will be restored ASAP. We apologize for any inconvenience."

Apple also admitted that earlier today iCloud had been slow to respond to log-in requests and to process required verification emails, but claimed those had been resolved.

"Due to high demand, we are temporarily limiting the number of users moving from MobileMe to iCloud," the MobileMe status page stated, explaining the failed migrations reported by users. "Please try again later."

After the MobileMe's launch debacle in 2008, Apple extended subscriptions by 30 days and turned the service over to a different executive. Jobs also issued a blistering internal email to employees that said MobileMe was "not up to Apple standards" and that it had been a mistake to launch it alongside the debut of the iPhone 3G and the new App Store.

In that 2008 email, Jobs said, "The MobileMe launch clearly demonstrates that we have more to learn about Internet services. And learn we will."

Before accessing iCloud, users must install iOS 5 on their mobile device, or upgrade to Mac OS X 10.7.2 on their Mac. Apple released both upgrades Wednesday.